1. Field of the Invention
The invention relates generally to a hydrostatic assembly having a primary pump and at least one secondary pump wherein the primary pump is a swash plate type axial piston motor having a cylindrical drum connected to an input shaft for rotation therewith and the closed end of the cylindrical drum is located adjacent to a control surface which is formed integrally with a control base or is a separate element attached to the control base. The secondary pump drives the primary pump by means of the input shaft.
2. Description of the Prior Art
This type of hydrostatic assembly generally includes standard individual pumps, such as an axial piston motor which operates as the primary pump and a gear pump which operates as the secondary pump. However, there are arrangements wherein two axial piston motors are connected. These assemblies are usually used to drive working machines, such as construction machines. The prior art also discloses the integration of a generic assembly with hydrostatic swash plate type axial piston motors having additional components in order to form a compact axle.
In addition to the structural length resulting from lining up individual conventional modules, a disadvantage of the prior art assemblies is the cost of the large number of components and of the installation. This is particularly true if the secondary pump is an axial piston motor.